The Opti in my '96 was running strong at 163K when I sold it 2014. Now in the 8 years I owned the car, I replaced the ICM, the Coil, the plugs and wires (several times) the fuel regulator, the fuel pump. Even the Opti harness. All of these things that when the symptoms appear, everyone says, 'it's the Optispark)

I even had the top radiator hose blow out on the highway, coolant flying everywhere in the engine bay. Did not effect the Optispark.

Fiber Optics was the tech of the day that allowed them to set timing and fuel delivery more accurately. That's how they got the power they did out of the LT1/LT4 engine and still meet the ever increasing fuel efficiency guide lines.

In 1994, they changed the design to being vented with fresh air from the intake manifold. Some of the late '94's got this I believe but it was in all the '95 and '96 cars. Many think they changed it to help with water intrusion. This is actually not the reason for the re-design. What they discovered was that because the unit was sealed, the arching from the rotor created an acidic gas that would eat away at the electrodes, and this was the leading cause of the untimely death of Optisparks. The ventilation was to sweep out that acidic gas.

 

I agree...but will add that I feel that in 90% of these failures, the "failed" opti is nothing more than dirty/contaminated lenses in the optical unit. I believe this b/c I've cleaned a couple that ha "failed from coolant" and after cleaning, they worked fine. I'd bet that MOST OEM opti's that failed were replaced (and "hated on") when all they needed was a simple cleaning then put back into service.


.

 

I'm on my 4th now, but a lot of trouble was my own doing. 1st was the water pump dripped antifreeze into it. (the most common reason for failure) 2nd was my fault. I over oiled my K&N filter and the vent pulled in a fog of K&N oil until if fowled the optic sensor. #3 was a misdiagnose that turned out to be a bad injector, so now I have a spare opti !

 

Either way the opti is better than the British electrical systems...anybody remember Lucas, the prince of darkness ? Or his Italian cousin Luigi Magnetti-Marelli ? The latter was how I learned to cuss in Italian.

later, tiny

 

the oem vented 95-96 ones dont fail unless seals crack and vent gets clogged or something.

i love it when i hear about the fool that 'heard optisparks fail' so they got and proactively replace their working fine oem optispark with an msd or made in china optispark. when it fails they complain that the optispark is a piece of junk.

all an oem 95-96 unit needs is a rotor/cap replacement (along with new wires and plugs). the base mitsubishi optical sensor wont fail , again unless the seals crack and vent clogs allowing moisture intrusion of sort.

the 92-94 optispark has a design flaw. it needs a vent setup (can be added) to make it reliable in the event the seals crack (which they usually do)

note the vented optispark was used on camaros, cadillacs, impala ss, buickroadmaster - taxicabs, police cars.

only the vettes have trouble and its bc the vettes 92-94 optispark is not vented

 

this is why i pull my vent from a hose/small filter inside the cabin !

 

Have to agree diz. I spoke to an older gentleman, and he was telling me he was going to "replace opti as preventative maintenance". Told him not to, if he's not having any problems. But he insisted

 

ask him for his old working fine OEM gen2 optispark - since you cant get them anymore.

steal it from him for $25-50

 

The bearing in the Opti failed on my '95. It felt questionable in my '96. Cap and rotor would've guaranteed a return trip.

 

Yes. I had a Ducati. They were nicknamed "Prince of Darkness" for a reason.

I saw this picture a few years ago (maybe someone here posted it, but I don't remember). I think it sums it up pretty well.

 

Yep Renfield, I'll go along with all of that. It is a 20 year old or so car that was never really designed to be around that long. No auto maker is concerned with the difficulty of repairs once the warranty is done. Indeed replace every "consumable" part while you're in there and call it a day. My greatest concern is the lack of a quality replacement part. I recently tackled the distributor on my 73. While new points, cap and condenser is just a few bucks they are all of questionable quality. I replaced the points/condenser with a new electronic unit from Pertronics for well under $100. I'm hoping it will work as well as the stock parts, which gave me no trouble in my 20 years of ownership. I understand there are a couple of high end Opti replacements that claim to perform well. When the time comes I'll certainly go that route. I don't mind performing any maintenance on my cars, I just hate having to do them over again.

 

The optispark system is extremely effective at managing the spark timing and coaxing maximum power out of the LT engines. Inputs from various sensors including knock sensors, throttle position sensor, temperature sensor, O2 sensors, etc. all contribute toward an excellent engine management system. I like it, for the most part.

The only real problem with the opti is that it's buried in a deep dark location and hard to access. Otherwise, the vented opti (1995-1996 LT engines) is no more problematic than other distributors. Even if the water pump leaks or blows out, the opti should be OK unless the cap and vent tubes are not sealed.

 

The optispark gets unwarranted hate most of the time. It was a great design, with good intentions from the start. Its just that the placement of it wasn't the best and early versions weren't vented. Most of the crap you hear people talk about it either never owned a lt1 car, messed up the installation, and/or bought cheap chinese versions.

 

Did anyone mention the Rotor screws that loosen and fall off over time?
One of my screws backed out and fell to the bottom of the cap and the other screw was loose. My rotor and cap were toast.
This happened around the time my water pump puked on it (around 41,500 miles). I originally thought the internals of the opti got wet from the water pump but it did not!
When the rotor screws come out you can have a miss under load or it might not start/run (my symptoms were the first).
I purchased a new GM cap and rotor/seal kit and that repaired the problem.
The Optispark isn't a terrible design but it was placed poorly and it has poor aftermarket quality support. I think this is why people don't care for the optispark.

 

I just love being told that my personal experience with not one but two Optishits was all but unheard of. Yea, I'm sure both my '95 and my '96 were just isolated incidents. It's really a flawless arrangement. I'm just talking crap.

You run that b.s game, friend.

 

It's easy to forget that the majority of threads in auto forums are seeking help for a certain problem. So naturally most of the posts about the Optispark are about problems. I could probably count on one hand the number of CF threads about "my opti works fine!" If we got all LT owners to post what happened with their opti, I bet the vast majority says no problem, assuming inspections were done as recommended and replaced any vent hoses or other parts as needed. Every distributor needs attention from time to time. The loose rotor screws are also an exception. They seem more of a problem than they really are because people enjoying problem-free cars are not posting.

In this linked thread, see posts #6 and 8:
https://www.corvetteforum.com/forums...opitspark.html

Posts #8 and 10 are interesting here:
https://www.corvetteforum.com/forums...optispark.html

Another example: consider that the LT is designed to run slightly higher temps than other motors of that time. We see lots of people complaining or very concerned about this. There are tons of posts about "high engine temps" when the system is actually working as designed. Maybe some cleaning and maintenance is needed, as is true with nearly all cooling systems. But among all LT owners, how many *actual failures* can be attributed to higher engine temperatures? Probably just hasn't been flushed in a long time and/ or there's 20 years of road debris buildup on the radiator... or the pressure cap is 15 years old! Just another design that gets a bad rap.

The majority of LT owners do not have opti issues like you've had, and posts like yours get undue attention. The overall result makes the opti sound like a pile of crap, which it is not. Surely it's not perfect, but it's not completely worthless either.

 

I think the Opti deserves the bad rap, the Camaro forums had problems with them too (although in the F body they are probably a bit easier to remove than the Y body). The optical part of the distributor is an OK design but they didn't have to put it under the weep hole of the water pump. Also only one manufacturer made a reliable sensor (Mitsubishi and they have been discontinued). The rotor screws are flimsy and loosen up. Location of the Opti sucks, a harmonic balancer that is fused onto the crank hub (even if the car was babied and never saw road salt or much rain). Never mind the fact you can't even put a puller on the damn thing (hub) because part of the frame sits right in front of the balancer. Stupid engineering design as a whole!!!!
I have owned my car and maintained it myself for 21 years (since new) and it runs like new but that opti was a bitch to replace.
I have no regrets owning the Vette at all but the Opti design needed more thought by the engineers.

 

Well said. Renfield seems to be a C4 hater in general.

 

Thanks for the analysis Doctor. And for trying to devalue my personal experience with these cars.

Maybe you're right. Maybe I am from Mars and these cars are effing FLAWLESS! Honda is jealous. Elon Musk is calling to find out how the hell they came up with an Optispark. He's hoping he can find a place for it on a Tesla!

Do all the "C4 haters in general" own two? That's what it took. Actually owning and wrenching on two C4s.

Defend the indefensible all you like. The OP is in for a GM hose job.

 

Well, that was a lot of stuff that I didn't actually say.

As you were, man.